This document summarizes a capstone project that studied the adsorption of phenol from aqueous solution using biochar produced from algal biomass. The project aimed to culture the microalgae Spirulina platensis and use it to produce biochar for removing phenol contamination. Experiments tested the effect of biochar dosage, pH, and contact time on phenol adsorption efficiency. Results showed the optimal conditions for removal were a pH of 7, concentration of 150mg/L, rotation of 150, and 0.4g of biochar over 60 minutes, achieving around 42% phenol removal. The biochar demonstrated potential for treating wastewater contaminated with phenolic compounds.

1. Capstone Project
(CLE4099)
By: Sagar Sonkar - 15BCL0263
Parth Bathla - 15BCL0346
ADSORPTION OF PHENOL FROM AQUEOUS SOLUTION
USING ALGAL BIOCHAR
Project Guide: Prof. Shantha Kumar S
REVIEW 3

2. 1. INTRODUCTION
 Although the food and beverage industries are not as polluting as some other sectors
like metal or leather industries, but they have been responsible for air, water and soil
pollution by emitting dust and unpleasant odor in the air.
 If the effluents from the food and beverage industry are contaminated with toxic
metals, these can affect adversely on human health.
 Phenolic compounds which are present in various concentrations in several of these
waste streams cause toxic effects and are reported as Cancer causing and may also
cause long-term ecological damage.

3.  Microalgae have been reported to accumulate pollutants such as heavy metals,
hexachlorobenzene, herbicides, insecticides and even Phenol.
 Spirulina Platensis, that was commonly used as nutritional supplements, could be easily
cultured, and the species were shown to thrive in municipal and agricultural wastewater
effluents for removal of contaminants by production of biochar.
 The most common method for the removal of this dissolved organic material is the
adsorption with activated carbon, a product that is produced from a variety of
carbonaceous materials and biochar is one of it.

4. 2. OBJECTIVES
 The work focuses on the ways to protect our surroundings from phenolic compounds in
waste water flushed out from industries by utilizing the biochar prepared from algal
biomass as adsorbent in the adsorption process.
 To culture Spirulina Platensis and use it to convert it into biochar to degrade the phenol
concentration.
 To study amount of biochar consumption so as to check removal efficiency of Phenol from
the aqueous solution. So that the quality of discharged water is improved to reach the
permissible level of water to be discharged into water bodies or for agricultural land.

5. 3. MATERIALS & METHODOLGY
 The microalgae species Spirulina Platensis have been chosen for this study collected
from the environmental engineering laboratory. BG 11 medium was used as a culture
medium for indoor cultivation.
 A stock solution of 150 mg/L of Phenol was obtained using standard crystalline Phenol
and the test solutions of various parameters such as pH, Dosage, etc. were prepared.
 BG 11 Broth is a universal medium for the
cultivation and maintenance of blue green algae
which helps in supporting growth of algae in light as
a source of energy.

6. 3.1 Culture Conditions
 Microalgae was cultured using BG 11 medium (BG 11 Broth 1.627 gm per liter). The
light source was provided by artificial illumination with irradiation of 5000 lux for
photoperiod of 24 hours.
 After the microalgae species reached the exponential
phase of growth, the biomass was used to further
cultivation in order to make the required number of
trials for the study.
 Then to expand the culture an artificial environment
was made using a cardboard box entrained with 25
Watt CFL and covered with Aluminum foil for the
multiple reflection.

7. 3.3 Extraction of Algae
 After culturing the species, the algal biomass was separated using Research Centrifuge
at 2000 rpm and the biomass was dried under room temperature and then oven dried for
complete removal of moisture content in the biomass.
 The dried biomass stored in the sample containers.

8. 3.2 Biochar Conditions
 The dry biomass extracted from above culture was used as raw material to prepare
biochar. The collected dry biomass was washed with tap water and then distilled water
thrice to remove any undesirable chemicals.
 It is then followed by sun drying for 24 h. It was
further dried in hot air oven to remove any moisture
content for another 24 h.
 The dried algal biomass was converted to biochar
using muffle furnace.

9. 3.4 Biochar Production
 Cultured and dried biomass was taken and grinded over sieve and sealed in air tight
container.
 In our study, 10 g of dried SP algae was fed into in a
tubular furnace.
 The dried powder then is taken in a certain amount in
the small crucible and placed in a muffle furnace, with
10 C/min heating rate to the target temperature (500
C) and then kept constant for 2 h.

10. 3.2 Phenol Bioassays
 The Standard Phenol is used to form a stock solution of 150mg/L by adding 150mg of
crystalline Phenol in 1000mL of distilled water. Then pH is checked and found to be
5.2.
 UV Spectrophotometer was used to check the
phenol concentrations for different dosages of
biochar in the phenol solution.
 Before that the machine is calibrated with the blank
distilled water and the phenol solution without the
adsorbent.
0
0.5
1
1.5
2
2.5
240 250 260 270 280 290 300
Abs
Wavelength (nm)

11. 4. RESULT & DISCUSSION
 The residue from SP extraction exhibits a promising potential as source of biomass for
pyrolysis. With a relatively high volatile content and carbohydrates content, pyrolysis of
SP produces a reasonable amount. The heating rate of pyrolysis required for the activation
energy was the lowest at 10°C/min.
 3 Trials were done varying the following parameters making everything else constant:
1. Effect of Dosage on adsorption
2. Effect of pH on adsorption
3. Effect of Time on adsorption

12. 4.1 Photometer Wavelength Spectrum
0
0.5
1
1.5
2
2.5
240 250 260 270 280 290 300
Absorbance
Wavelength (nm)
 The calibrated maximum
wavelength under which phenol
concentration has to be checked
was found out to be 268 nm.
λmax = 268nm

13. 4.2 Effect of Dosage on adsorption
 Samples of phenol concentration of 150 mg/L were placed in 100 mL conical flask(250
mL) for 5 samples, adding 0.2 g, 0.4 g, 0.6 g, 0.8 g and 1.0 g, respectively, in order to
determine the residual phenol concentration keeping certain factors constants.
 Constant Parameters:
Initial Concentration = 150mg/L
RPM = 150
Time = 60 min
pH = 7

14. Dosage Initial 60 minutes
% Removal
0.2 2.080 1.469 29.33
0.4 2.080 1.177 43.41
0.6 2.080 1.609 22.64
0.8 2.080 1.625 21.88
1.0 2.080 1.752 15.77
0
5
10
15
20
25
30
35
40
45
50
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
%removal
Biochar(g)
4.2.1 Values & Graph

15. 4.3 Effect of pH on adsorption
 Samples of phenol concentration of 150 mg/L were placed in 100 mL conical flask for 4
samples of different pH (3, 5, 7, 9), adding HNO3 to alter the pH to acidic from neutral or
by adding NaOH to alter the pH to alkaline from neutral. The experiment was conducted
with the following conditions.
 Constant Parameters:
Initial Concentration = 150mg/L
RPM = 150
Time = 60 min
Dosage = 0.2 g

16. 4.3.1 Values & Graph
pH 3 5 7 9
% Removal 9.23 27.84 40.87 18.80
0
5
10
15
20
25
30
35
40
45
3 4 5 6 7 8 9
Removalefficiency
pH

17. 4.4 Effect of time on adsorption
 Samples of phenol concentration of 150 mg/L were placed in 100 mL conical flask for 4
samples at different time intervals for 30 minutes, 60 minutes, 90 minutes and 120
minutes. The residual phenol concentration was determined by keeping certain factors as
constants.
 Constant Parameters:
Initial Concentration = 150mg/L
RPM = 150
pH = 7
Dosage = 0.4 g

18. 4.4.1 Values & Graph
pH 3 5 7 9
% Removal 9.23 27.84 40.87 18.80
Time Interval 30 60 90 120
% Removal 41.83 33.17 22.64 21.88
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
30 40 50 60 70 80 90 100 110 120
%removal
time (min)

19. 5. CONCLUSION
 This study investigated the tolerance and bio-sorption capability of Spirulina Platensis
using synthetic phenol contaminated water.
 Results from the tolerance study showed that SP cells were capable of adsorbing the
phenol. During the experiments, phenol was remarkably removed and biodegraded
within the first 60 minutes with optimal conditions of 7 pH, 150mg/L concentration
and 150 rotations for 0.4 g of biochar. This suggested that the removal of phenol was
mainly due to bio-adsorption processes.
 It can also be said from the study that for SP algae the optimum results are obtained
when the pH is 7.

20.  Furthermore, it is also seen that for first 30 minutes the removal is efficient when the
parameters concentration, rotation and pH were held constant for the dosage of 0.4 g
of adsorbent.
 Based on the above discussion it is also clear that the high temperatures of pyrolysis
condition viz 450 to 600°C are good enough for the preparation of biochar for the
biomass of Spirulina.
 So at the end the average effective phenol removal efficiency of Spirulina Biochar
taking all the trials into consideration comes out to be 42.0367 %.

21. THANK YOU